import _curry1 from './internal/_curry1.js';
import assocPath from './assocPath.js';
import lens from './lens.js';
import _path from './internal/_path.js';


/**
 * Returns a lens whose focus is the specified path.
 *
 * @func
 * @memberOf R
 * @since v0.19.0
 * @category Object
 * @typedefn Idx = String | Int | Symbol
 * @typedefn Lens s a = Functor f => (a -> f a) -> s -> f s
 * @sig [Idx] -> Lens s a
 * @param {Array} path The path to use.
 * @return {Lens}
 * @see R.view, R.set, R.over
 * @example
 *
 *      const xHeadYLens = R.lensPath(['x', 0, 'y']);
 *
 *      R.view(xHeadYLens, {x: [{y: 2, z: 3}, {y: 4, z: 5}]});
 *      //=> 2
 *      R.set(xHeadYLens, 1, {x: [{y: 2, z: 3}, {y: 4, z: 5}]});
 *      //=> {x: [{y: 1, z: 3}, {y: 4, z: 5}]}
 *      R.over(xHeadYLens, R.negate, {x: [{y: 2, z: 3}, {y: 4, z: 5}]});
 *      //=> {x: [{y: -2, z: 3}, {y: 4, z: 5}]}
 */

var lensPath = _curry1(function lensPath(p) {
  return lens(
    function(val) { return _path(p, val);},
    assocPath(p)
  );
});
export default lensPath;